1. Field of the Invention
The present invention relates to a stator manufacturing apparatus for joining a plurality of separate cores, each carrying a coil wound thereon, into an annular stator.
2. Description of the Related Art
Heretofore, there has been known a stator for electric rotary machines, which comprises a plurality of interconnected separate cores. Each of the separate cores comprises an arcuate yoke, a pole extending radially inward from the yoke, and a coil wound around the pole.
The yoke for each of the separate cores has a recess defined in a portion thereof, and a tooth provided on another portion thereof. The recess of the yoke of one of the separate cores receives therein the tooth of the yoke of an adjacent right-hand separate core, and also receives the tooth of the yoke of one of the separate cores that is fitted into the recess of the yoke of an adjacent left-hand separate core. The yokes are thus interconnected by an interfitting engagement of recesses and teeth, thereby combining the separate cores into an annular stator.
For the purpose of improving performance of electric rotary machines having such a stator, attempts have been made in the art to increase the number of windings of the coil on each separate core, so as to increase the space factor of slots between the poles. For example, Japanese Laid-Open Patent Publication No. 11-341748 discloses a stator assembling method, whereby the coil wound around a pole is compressed to reduce the occupied volume of the coil and thereby increase the space factor.
Specifically, a winding is wound a plurality of times around the pole to form a coil, which is greater in size than the coil storage space that accommodates the coil. In this manner, a plurality of separate cores are produced. Then, the separate cores are arranged in an annular pattern with insulators inserted between adjacent coils of the separate cores.
The annularly arranged separate cores are then compressed and displaced radially inward. The coils of adjacent separate cores, with the insulators interposed therebetween, are pressed together. Also, windings that are positioned outside of the coil storage spaces are pressed into the coil storage spaces.
With the windings pressed into the coil storage spaces, the separate cores are joined together into an annular stator.
Therefore, it has been known in the art to arrange a plurality of separate cores in an annular pattern, and thereafter displace the separate cores simultaneously radially inward to compress the coils. However, Japanese Laid-Open Patent Publication No. 11-341748 discloses nothing concerning structural apparatus details for carrying out the above method.